1. Field of the Invention
This invention relates to controlling the simmering or cooking time in a cooking vessel which can be heated by means of an electrical cooking plate with a control circuit, in which the temperature in or on the cooking vessel is determined and utilized by the control circuit to regulate the heat output of the cooking plate, in which the simmering or cooking time can be set by means of an adjustable time element. The cooking plate can be shut off at a length of time before the completion of the predetermined simmering or cooking time, which shut off time difference is greater with the greater the heat quantity determined from data from the heating phase, and thus the cooling time of the resulting cooling process after the switching off of the cooking plate is greater.
2. Description of the Prior Art
German Patent Publication DE-OS No. 33 14 398 teaches a device in which information is obtained from the rise in the temperature during the heating phase as to the quantity of preferably fluid cooking material is contained in the cooking vessel, and how, as a result, the cooling process proceeds after the cooking plate is switched off. In this manner, the cooling process can be utilized to extend the simmering or cooking time. In this system it is to be considered that the simmering effect on the food is halved for approximately every 10.degree. C. of reduction in temperature. It is therefore reasonable to only consider the secondary simmering after disconnecting the cooking plate up to the drop to approximately the boiling temperature of water with a steam pressure cooking pan in the pressure-free condition. The energy expenditure for the simmering or cooking process is thereby reduced to the minimum level, and an undesired extension of the simmering or cooking process by the cooling process is avoided. The simmering or cooking process set by the simmering or cooking time is thus maintained with regard to the quantity of cooking material in the cooking vessel and the cooling process which specifically arises.
German Patent Publication No. 33 16 799 teaches a device for a steam pressure cooking pan, in which the time period for attaining the temperature necessary for initialing significant steam formation is utilized up to reaching of the boiling temperature of the water, in order to obtain information as to how great the quantity of preferably solid cooking material is above the water bath. With an increasing quantity of cooking material, this time period correspondingly increases, and the heat quantity stored in the cooking material, rises correspondingly, so that the cooking plate can be correspondingly shut off in advance. The predetermined simmering or cooking time is correspondingly extended through the cooling phase, and thus maintained. With increasing time length, the disconnection of the cooking plate can thus be initiated correspondingly earlier.
It is also known to utilize both the increase of the temperature in the heating phase, as well as the time period which extends from the reaching of the temperature necessary for the initiation of significant steam formation up to the reaching of the boiling temperature of the water, in a device for the early switching off of the cooking plate, as German Patent Publication No. 33 23 399 demonstrates. In this system, the time span for shortening the on time of the cooking plate is derived from both forms of information. With a predetermined maximum increase of the temperature in the heating phase, only the predetermined time period for deriving the time period is utilized.
It has been shown that even when determining the increase of the temperature during the heating phase, false measurements are obtained if, when turning on the cooking plate, the starting temperature of the cooking material lies above room temperature. The increase in the temperature during the temperature measurement time changes with the same quantity of cooking material in dependence on the starting temperature. With increasing starting temperature, the increase in the temperature during the measurement time is slower. A larger quantity of cooking material is therefore misrepresented, and the derived shortened time span is thereby too great. The consequence of this is that the cooling process is too short and that, with the premature switching off of the cooking plate, the cooling phase is not sufficient to maintain the simmering or cooking time long enough for the predetermined simmering or cooking time to be attained. Higher starting temperatures are, however, frequently present. There should only be recalled the thorough searing of food in the cooking vessel. In this case, the cooking vessel is heated, and the food is then, for example, spoiled by the hot sludge. In this case, the starting temperature is, rather, in the temperature range between the temperature necessary to initiate a significant steam formation and the boiling temperature of the water. With these high starting temperatures, the heating phase up to the boiling temperature is no longer suited to obtain information about the cooling phase to be expected.